#define _CRT_SECURE_NO_WARNINGS
class Solution {
public:
    int multiply(int A, int B) {
        if (B == 0) return 0;
        if (B == 1) return A;
        int C = 0;
        if (B & 1 > 0) {
            C = A;
        }
        return multiply(A, B >> 1) + multiply(A, B >> 1) + C;
    }
};

